Scientists Looked For Laser Signals From The "Alien Megastructure" Star. This Is What They Found

Since its discovery three-and-a-half years ago, Boyajian’s star has fascinated professional astronomers as well as lay people alike. The star, also known as KIC 8462852, experienced unusual brightness fluctuations, which still remain without explanation.

Many naturally occurring phenomena have been proposed to solve the mystery – and, of course, some artificial ones. The star famously became known as the "alien megastructure" star, as some thought the changes in luminosity might be due to a large orbiting structure that could be used by an alien civilization to collect energy from the star.

Researchers have looked at this star time and time again, to see if they can spot any peculiar features that may aid them in the mystery. If there truly was a huge structure orbiting this star, how would the aliens transmit information and energy to and from it? The most likely answer is lasers, so researchers at the Breakthrough Listen Project have been looking for laser signals from the star. They didn’t find any.

The team analyzed 117 high-resolution spectra from Boyajian’s star using the Lick Observatory in California. Given the tech of the telescope and that the star is 1,470 light-years away, the team estimated that any laser more powerful than 24 megawatts would be detectable; powerful but not incredibly powerful (we developed megawatts lasers in the 1960s).

Nothing even close was seen by the team, led by David Lipman (then a high-school student, now at Princeton), who wrote an algorithm that sifts through the data. The top candidates in the study were either cosmic ray hits, regular stellar emission lines, or emission from our own atmosphere. The observations are reported in a paper available to read now on ArXiv, and it is published in the Proceedings of the Astronomical Society of the Pacific.

While the alien explanation has gone from the very unlikely to the extremely unlikely, the search for an answer goes on. Dr Tabetha Boyajian, lead author of the original discovery paper, continues to lead the community-funded efforts to study KIC 8462852. As posted on the project blog, the team has just restarted observations of the object in the hope of finally working out what’s going on. The main hypothesis is that the star is surrounded by a patchy donut of dust.

Boyajian’s star has gone through many names. It was also known as Tabby’s star after Dr Boyajian, though this is being phased out as objects named after people should be referred to by their surname. And at the very beginning, it was called the WTF star because the puzzled astronomers were very curious about “Where the Flux” of the star went as its brightness changed.